The overall goal of this Project 6 is a combined core facility, cell bank, clinical data base and research project. The research objective of Project 6 is to interact with Projects 1, 2 and 3 by providing an integrated centralized data base for the studies of class I HLA-A,B,C molecular variants (Project 3) and the new class I HLA-E, F(5.4) and G(6.0) molecular variants. The eventual clinical analysis will be performed with the combined data using multivariate methods. The overall goal is to determine the impact of HLA incompatibility on the incidence and severity of graft- versus-host disease (GVHD). The core component of this project will focus on accumulating biological materials from patients and unrelated donors and establishing a cell bank of EBV-transformed B-lymphoblastoid cell lines (LCL) Clinical and laboratory data will be collected and key entered for computer analysis. As data are acquired to define the polymorphism for MHC class I and class II loci, appropriate statistical analysis will be undertaken periodically to assess whether the prevalence of disparity for any given locus is sufficient to allow clinical correlations to be made. Finally, Project 6 will provide core administrative and secretarial support for the entire program project to assist in the planning of research meetings and seminars, management of budgets and preparation of correspondence, reports and publications.